Mortar and stucco normally consists of the combination of cement and sand in a ratio of approximately three (3) parts sand to one (1) part cement. Directions for specific brands of cement usually call for from 2.25:1 to 3:1 sand to cement ratios. The cement is generally mixed at the job-site in a gasoline or electric powered mortar mixers. Often, the sand is delivered in bulk, while the cement mix is delivered in bags weighing either 78 or 80 pounds. Due to the weight of the bags, they are often delivered on palates and lifted with fork lifts and/or cranes. One bag of cement mix is mixed with approximately three cubic feet of sand. Water is added to achieve a consistency that allows good workability. While the term sand is used throughout this disclosure for ease of discussion, those skilled in the art will recognize that sand may include other heavy aggregates, such as gravel, crushed stone and the like.
The weight and volume of these bags of cement create several problems. During storage, the weight and volume relate to the total storage space required and the cost of transporting within the warehouse. During transportation, the volume and weight affect the total number of bags that fit within a given truck and the fuel consumption required to transport the bags to the construction site. At the construction site, the weight becomes more of an issue since individual bags are often lifted by a worker and many bags are lifted per day, the 78-80 pound bags cause fatigue and are the cause of many stress-related ailments.
U.S. Pat. No. 5,718,758 to Breslauer recognizes that mortars of the prior art create problems due to weight, leading to worker injury during carrying of the mortar, etc.
Other cement compositions disclosed in U.S. Pat. No. 6,840,996 to Morioka, et al, U.S. Pat. No. 7,070,647 to Fujimori, et al, and U.S. Pat. No. 7,148,270 to Bowe describe various cement compositions, none of which provide a light-weight ready-mix composition.
What is needed is a light-weight, cement mix for mixing with sand for masonry, mortar and stucco.